Is it possible for an object movisckah ssh- (c(/gz :.fng with a constant speed to accelerate? Explaingsccsskh/ -(( fah. z:.

  Consider a particle moving with constant speed such that its acc a4 qk:arwoo++4qocc :eleration of constant magni o+a cqoro 4ck4::qaw+tude is always perpendicular to its velocity.

  An object moves in a circular path 1k,-iqv s4 ccxo.;ukeat a constant speed. Compare the direction of the object's velo q 1s,cecik.4vk;u-xocity and acceleration vectors.

  When an object experiences uniform circular motion, the direcjlj2994aqeggy 8/ igution of the acceleg89gg2 eua/lqyij 4 9jration is

  Consider a particle moving with constant speed such that it qo 4q8e6:z0c8wp klmas acceleration of constant magnitude is always perpendicular to its velqwm6e84q al 0c:z8 kpoocity.

  What type of acceleration n* *ma v7 +0m5uyquc6(vla kncdoes an object moving with constant speed in a circular path expenk c*aym *m0nl(uuav65c +7vqrience?

  What force is needed to make aav9,ix w-y-w ln object move in a circle?

  When an object experiences un,:sx7g qqbtr,.satq9(g8 c t miform circular motion, the direction of the net force isr:mqaqgs ( q8s .7,tc9b ,tgxt

  A roller coaster car is on a track that forms aen-w*h k7 yhjh t;jx01 gkg* oge2jv.6 circular loop in the vertical plane. If th 71kvt*h2 e-jj*og;ke .gjhx g6hwn0ye car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (r 6( g:gqse,g iv+dunk4adius = r) in the vertical pla ,: 6(dvgggknu qei+4sne. If the car is to just maintain contact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical di-gr p6 8(sabvwve then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him v wb(-pg sr68ais

  A coin of mass $m$ rests on a turntable a distance $r$ from the axis of rotation. The turntable rotates with a frequency of $f$. What is the minimum coefficient of static friction between the turntable and the coin if the coin is not to slip?

  A car goes around a curve of r8p5py .f jt jt(o,kv( 7mkg5tjadius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius r at a constant speed v. Then itu l5hs6c; vsptm: 8 t8o51ezoq goes around the same curve at half of the original speed. What is the centripo:81t5lv; et6ssqh8u5cmz opetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it go7j/ xi0jqhem 2es around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, co2i hj j0mq7x/empared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If the rosq 3mhlh 71wg(ad is frictionless due to ice, the cawshg1(h3q7 ml r can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the samrtel *lsx,f: na-p27i*z-kolusnh07bf u5p 0e angle, but one has twice the radius of the other. The safe speed (no friction needed to stay 2t*:n-ie5s ,-sal7flhnuoulp 0 0fb*pxkzr 7on the run) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, but inz 8:fyumcbh;uk3y jkzi,o6n98a c8a1( qea j 5creases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then q1 9n y3 jkcaik688:jyhzb5,(amoue8az ucf;go lower coming out of the turn. Why do they do this?

  Is it possible for an object mov.3r(hvhcgss +oj )6p*sbh c0aq dxp:*ing around a circular path to have both centripetal h+hqj*) h3vrs: c0(dspxga. b psc6o*and tangential acceleration?

  The gravitational force between two objectsw,+f9i7+vl .5 rh(f shiuzjho is proportional to

  The gravitational force betwe 0uj 0i drhaqgue *ylj8*r)3u)en two objects is inversely proportional to

  Two objects attract each other gravitationally. If the disq hf3g+(v)u9i kjsq ;i2up2kw tance between their centers is cut in half, the gravitational usfh+q9(2;p2)w uiik3gkq j vforce

  Two objects, with maso-/86 al9l(f p1aurqx td9n ssses $m_{1}$ and $m_{2}$, are originally a distance r apart. The gravitational force between them has magnitude F. The second object has its mass changed to 2$m_{2}$, and the distance is changed to r/4. What is the magnitude of the new gravitational force?

  Two objects, with masse)x87ga+xbe wyy)o- ictj+jm8 s $m_{1}$ and $m_{2}$, are originally a distance r apart. The magnitude of the gravitational force between them is F. The masses are changed to 2$m_{1}$ and 2$m_{2}$, and the distance is changed to 4r. What is the magnitude of the new gravitational force?

State Newton's law ofwosbn;.4wf ug90ru+zm,g5x j universal gravitation.

  Compared to its mass on the Eaf(xzx +mx6khx( )mk 9xrth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what m(tgnkg9bn *2i- k epvqi*z8/it is on Earth. An obink2* p/vmg*nki(8b-qg tz9 eject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Eou 2 *i6i,1qsmngf0anarth's surface, the rocket's weight

  A spaceship is traveling tj-l 9if8x sqmlxfp p ,/jbx7-;o the Moon. At what point is it beyond the pull of Earth's gri sf-7jxlpqx;pmxf/jlb 8 9 ,-avity?

  Suppose a satellite were orbiting the Earth just above the surface.b q;oxk sud4v0m1r d+7rpkb0, What is its centripetal acceleramk1,k q00 xd7+p4 rsb dv;uobrtion?

  A hypothetical planet has a mass of half that of the Earth and a radius x3ndjia+,j si9g;par3wc-)e of twice that of the Earth. What is the acceleration due to gravity on the cw+xn)ig ;-jd j,isa 3r3 9epaplanet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity oa xr/lhw* h*+dif4o3n n the Moon is one-sixth what it is on Earth. The radius nd o4+h /f hr*ixwl*a3of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twicejnaekx/ u,un*c ini7,yal( *5nf22ze the radius of planet A. If planet A has mass m, what i ,zn7/inxkai (2*2jlc un5f,ya e u*nes the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass pcs*k: g8i6ommq,y 6m of planet A. If planet A has radius r, what is the radius of play g:ommp 6c*sqi6 ,km8net B?

  Consider a small satelli fjn7tdx4vbijt /k j-lmv/ xh0q9227 zte moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression givef4v/xhqz 0- li x2/2jv7d9j jkttnbm7s this satellite's orbital velocity?

  Satellite A has twicw6 d ;)gc6f i5ee1bnfse the mass of satellite B, and rotates in the same orbit. Comparei ebnwfd)156; efcsg6 the two satellite's speeds.

  A person is standing on s-ux7suk 4 j8-ob2ulya scale in an elevator accelerating downward. Compare the reading on the scale to tjsyso-x -k uubl248u7 he person's true weight.

  Who was the first person to realize t3r0ubtul)( a shat the planets move in elliptical paths arouabl 0tr(s3uu)nd the Sun?

  The speed of Halley's Comet, while traveling in i*4e-)wdjyk b 49osxrb ts elliptical orbit around the Sunwkbrxe*s j bd)4o-49y,

  Let the average orbital radius oik v o .hbt7sm4va*7 ysbj3/d5f a planet be R. Let the orbital period be T. Whaibdb7v./5 v 4aj syts*o3hmk7t quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a sta4aie3j e c;+b*9djmjcr in the galaxy Andromeda, with the same orbital diameter as the Earth around our Suaiec3* j+49mdjeb j;cn. If that star has 4 times the mass of our Sun, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astrol mow t; + vkq-jg;l)+wy) vc ez,,nu0f3mbfo0nomical unit" (AU). An asteroid orbits ;cl+ v3qf,kg mf woebzw;)ntm+ lou)00 v-, yjthe Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ycl:z/ r+2 omd7yd mg e151haq

  List the four fundamentc83(.tx 3mu so fmker r(p*k-pal forces in nature.

  An object moves with a constant speed of 30 m/s on a circular trac;q1qtg mqw.g8 k of radius 150 m. What is the acceleration of thtw gq. ;1q8mqge object?

  The maximum speed around a level curve is 30.0 km/h. Wha hebs-z) 6e/snt is the maximum speed around a curve with twi6)- es/b nzhesce the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleratio0 dxkk41 f3n7he,katdeblk 95n of a point on the perimeter of a bicycle wheel ba5kkle h4n k1k0d9d3x, f7t eof diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located;(vy9fbw2 h8 / v1sn ibo9ajpr 0ifz7i 0.200 m from the axis. What is the centripetal acceb8ij7b1i so v90 z;9vnrwpf2af(y/h ileration?

  How many revolutions per wyk04 )twk30hdh9bud minute must a circular, rotating space station of radius 1000 m rotate to prodk0hbyw d40hu3 dk)w 9tuce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a m;tyx-kjic(uf;d cp3wj9 xnhzn( y8 05ass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km9j5ij3h0npf 8unck ;yy -cz(tx(w;xd/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to tijid 4f(j93 -v2yz-jd9wg glthe end of a 1.0-m string. The system is whirled in a horizontal circular pag3 zgld4(jfdj9 9jt iv2i-y- wth. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong rda1n+)3vu- e.xr z u6i 2acomstring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stonu31rza e-+roia.xv6nm) cd u 2e's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical c+ b-s/o famznn).1p r- ta+egxircle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weight. The stone's sp-+/)s-r +1n xgabne .mfaozp teed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 8 *meoqg09ty1j kt50bpteh +a4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is8py 0 5e hok0 mja*q9+btt1egt flying?

  A pilot makes an outsid;tspl2jy (b2m c-3dzoe vertical loop (in which the center of the loop is beneath him) of yo(2 dj2lzt mb;3cps- radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times histr8ntz1zi(i 2m) vh- d weight. What is the minimum ramitdhtr n vi(1)2zz- 8dius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires on 14pkib gq8.sdthe verge of slipping. How fast can this car round a second curve of rd. 48gqbkspi1 adius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve o 9 cvr+8y:vxlg a1jed4f radius 50 m with a speed of 20 m/s. The centr jd9g+8r a lv:vxc4y1eipetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiuszbtxai996lui2 y 6 b4i6vxum0 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make ty64zblt6 vm ai u9i29iuxb6x0he turn?

  A car is moving with a constant speed v around a level curvexg8za g n,eik1*gwy(7jysj(: . The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of thkgxgs(j7*i z j:ay 8(ng1,wy ee curve if the car is to stay on the road?

  What minimum banking angl0v5f+n + deyele is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s wi5+denf +yv0 lethout skidding? (Ignore friction.)

  A horizontal curve on a bobmu *4jd-i0t apssy// rm ;ze-msled run is banked at a $45^{\circ}$ angle. When a bobsled rounds this curve at the curve's safe speed (no friction needed to stay on the run), what is its centripetal acceleration?

  A frictionless curve of radius 100 m, banked at an angle ofz/hkq1noz2b9)/z,dkb.hz eaa(g/ d u $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 msqiw; s:lnje /-e51mh-s 50adyq c7shsxp a85 is banked at $45^{\circ}$. Suppose that an ice storm hits, and the curve is effectively frictionless. What is the safe speed with which to take the curve without either sliding up or down?

  A 175-kg ball on the end of a string is rer.2 qxhcqp4a -volving uniformly in a horizontal circle ofqp4aq r-chx.2 radius 0.500
m. The ball makes 2.00 revolutions in a second. (only fill in numerial value in the blanks)
(a) Determine the speed of the ball.    $m/s$
(b) Determine the ball's centripetal acceleration.    $m/s^2$
(c) Determine the force a person must exert on opposite end of the string.    $N$

  Starting from rest in the pit area, a race car accelerates at a unifo+(m*:rayi r durm rate to a speed of 45 m/s in 15 s, mov+u (a:imy rd*ring on a circular track of radius 500 m. (only fill in numerical value in the blanks)
(a) Calculate the tangential acceleration.    $m/s^2$
(b) Calculate the radial acceleration when the instantaneous speed is equal to 30 m/s.    $m/s^2$

  The hydrogen atom consists of a n*hedod i8gm9k9 5q9j proton of mass $1.67 \times 10^{-27} \; kg$ and an orbiting electron of mass $9.11 \times 10^{-31} \; kg$. In one of its orbits, the electron is $5.3 \times 10^{-11} \; m$ from the proton. What is the mutual attractive force between the electron and proton?

  What is the gravitational ox 9dwjup, ;*sforce on a 70-kg person standing on the Earth, due to the Moon? The mass of the Moon p,wxuo9s ;dj*is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If tkr7n+bmazd. +he masses are moved to half of their initial distance, what isab+. r7ndmkz+ the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at wh 3ftoym)v ra176m ez-bat distance from the Earr1e bomyv67-a t)z3fmth will the gravitational forces due to the Sun and the Earth cancel?
Earth's mass: Me = $5.98 \times 10^{24} \; kg$ the Sun's mass: Ms = $1.99 \times 10^{30} \; kg$
Earth-Sun distance: r = $1.50 \times 10^{11} \; m$

  The mass of the Moon is p/xf vzi1m2zj 3q*h9h$7.4 \times 10^{22} \; kg$ and its mean radius is $1.75 \times 10^{3} \; km$. What is the acceleration due to gravity at the surface of the Moon?

  An astronaut goes out for a "space-walk" at a distance above th v9eh3f(v sz9ee Earth equal to the radius of the Eazehe9f s(vv39 rth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's sf4,kwm oh6p;q + wcd1xurface will the acce, op1c+;mhw4w k x6dfqleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its suy.*yqj:)hmke +5t,t u5omu berface equal to 3 times the radiumu:)oqu5h+*mkyt 5btj e, e .ys of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from z.f.hh5 s +4kd ywsne;some planet's center, the acceleration of gravityk+nfe5.s wzsd;.hy4 h is $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface of tha ai68 g,r9/ .,(j.dhoz fjjoi+kwl+)jamb lne Earth. The Earth has radius r. If the on+jjjk. wgd+h)b i al(86oj, fomar,9alz.i/bject is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chang +gmb v/m3-;d7zbtbl moy;*que when he goes from sea level to an altitude of 5000 m? (m3 tqzblmv +o-bu y7*;dgb /m;The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A sat;e0r;qc txv9r ellite of mass 100 kg is at a point 3r above the Earth's surface. Whxe;q09 ctr; rvat is the satellite's weight?

  A spherically symmetric4 k*k4 xhbtns- planet has four times the Earth's mass and twice its radius. If a jar of peans4-b*xnkt 4 khut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same libbz4hu5422sr tc suk *ne, with the Earth between the2hzsstb5cb 4u*k2u 4r Moon and the Sun. The Moon has a mass of $7.36 \times 10^{22} \; kg$; the Earth has a mass of $5.98 \times 10^{24} \; kg$; and the Sun has a mass of $1.99 \times 10^{30} \; kg$. The separation between the Moon and the Earth is given by $3.84 \times 10^{8} \; m$; the separation between the Earth and the Sun is given by $1.496 \times 10^{11} \; m$.
(a) Calculate the force exerted on the Earth by the Moon, its magnitude is    $\times 10^{20} \; N$, its direction is  ----待选择----towardsaway from  the moon.
(b) Calculate the force exerted on the Earth by the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.
(c) Calculate the net force exerted on the Earth by the Moon and the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.

  A 2.10-kg brass ball is transported to thxph,t6 y+ur4: vvjo .te Moon.
(a) Calculate the acceleration due to gravity on the Moon.    $m/s^2$ (The radius of the Moon is $1.74 \times 10^{6} \; m$ and the mass of the Moon is $7.35 \times 10^{22} \; kg$)
(b) Determine the mass of the brass ball on the Earth    $kg$ and on the Moon    $kg$
(c) Determine the weight of the brass ball on the Earth    $N$
(d) Determine the weight of the brass ball on the Moon    $N$

  A satellite is in a low circular orbit about the Earth (i.e.,upansbh wk7f9ct8 u8b(l3x(lk 2w- h1 it just skims the surface of the Earth). What is the speed of the satellite? (Th1k bkt su 7(3au9 -x82ch8 hplwf(wnlbe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just ski yp *tx+ 3ve/jy*it1sums the surface of the Earth). How long doe/e3us *j 1i+yt*tvp xys it take to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. It is p8hn/ r)34:tutnf ypqobserved to have a period of 89 min. What /tty qrfn3):u8pn4ph is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupi5a:2 udj vd8,yjqyszhk 75dct+3gt6 k ter, has an orbital diameter of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet w d q6w:tw)psf8ith a radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly circular orbits. Moon A has orbital rad:777 p:lydmfjspoar0 q,e5b sius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?77 7,ya ls0f5dr:p: sqjom peb

  The planet Jupiter i**f)pit8ba v xy)gk*gs $7.78 \times 10^{11} \; m$ from the Sun. How long does it take for Jupiter to orbit once about the Sun? (The distance from the Earth to the Sun is $1.50 \times 10^{11} \; m$.)

  It takes the planet Jupiter 12 years to orbit the S3wq6zw5 dt sy65g3u : f)sceumun once. What is the average distance fromcg)56m3y ft5ws u3uds: eqw6z Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)